In the dyeing of human hair with direct dyes as distinguished from oxidation dyes, the resultant final color is a combination of the natural hair color plus the color added by the dye. Other procedures utilizing oxidation dyes first eliminate the natural pigments of the hair through bleaching with an oxidizing agent such as alkaline hydrogen peroxide. Then the desired coloration is obtained on the hair by treating the hair with oxidation dyestuffs. Colored polymeric compounds of high molecular weight are produced on the hair by the action of atmospheric oxygen or by oxidizing agents such as hydrogen peroxide. Possible also is the carrying out of simultaneous bleaching and coloring. Concurrently hair is bleached by alkaline hydrogen peroxide as dyestuff penetrates into the hair and is oxidized to produce the desired color.
Usually, the whole operation of bleaching and coloring is accomplished by applying a mixture of oxidizing hair coloring and hydrogen peroxide prepared immediately before application. However, this method takes some time and is subject to errors of mixing yielding insufficient coloring or hair damage by use of excess peroxide. Where there is a delay for one reason or another in applying the mixture to the hair, undesirable coloring effects may result if a partially oxidized mixture is used.
The packaging of oxidizing compositions for hair coloring in containers for distribution under pressure can avoid certain of the disadvantages enumerated. Such a container has two separate interior compartments for maintaining separately the oxidation dye and peroxide portions under pressure. Necessarily, the contents are kept separate until actual use. The mixed composition remains useful only for a short time after it is mixed. Examples of such containers are given in U.S. Pat. Nos. 3,272,389; 3,341,418; and 2,973,883.
The oxidation dye solution lies in the body of the container with the hydrogen peroxide stored in a collapsable bag usually made of plastic material attached to the valve body and partially suspended in the oxidation dye solution. Mixing of the oxidation dye solution and the hydrogen peroxide occurs in the valve housing on actuation of the valve. The mixture coming from the nozzle of the can is directly applied onto the hair. There the mixture is worked into the hair and coloring of the hair occurs.
Dilute solutions (10-20%) of hydrogen peroxide are generally used in this type of package. The most stable of these commercial solutions of hydrogen peroxide slowly liberates oxygen. The liberated oxygen permeates the bag and gradually oxidizes the oxidation dye solution. As a result of this, an undesirable coloring effect will take place when the partially oxidized oxidation dye solution is used. Also, the bag containing the hydrogen peroxide is permeable to vapors from the oxidation dye solution which will lower the hydrogen peroxide stability, resulting in the generation of more oxygen.
Although the best guarantee for high stability of hydrogen peroxide is high purity, some substances prevent or slow down the decomposition for long periods of time. The anticatalytic or stabilizing action of these substances is due to their ability to remove positive catalysts. One group accomplishes this by forming complexes with heavy-metal ions, the other by absorbing these ions and thereby inactivating them. To the first group belong substances such as pyrophosphates, fluorides, cyanides, and some organic substances such as acetanilide, phenacetin, 8-hydroxy quinoline, hydroxy acridines and other chelating agents, examples of which are disclosed in U.S. Pats. Nos. 3,378,444 and 3,632,295; to the second group belong freshly precipitated alumina and silica, sodium stannate, and hydrous antimony and stannic oxides.
However, even in the presence of the most effectively known of these peroxide stabilizers, some peroxide decomposition occurs and oxygen is liberated. The terpenoid stabilizers of the present disclosure will react with this free oxygen, minimizing pressure buildup and permitting for less oxygen to permeate into the dye phase.
Generally, substances which react with oxygen are not stable in the presence of hydrogen peroxide; surprisingly the terpenoids disclosed herein appear to be.
To avoid gas interchange, aluminum-laminated bags can be used. This dose eliminate, to a great extent, vapor permeation into the bag and oxygen permeation out of the bag. However, oxygen is still being slowly liberated from the dilute hydrogen peroxide (10-20%). With more or less no means of escaping, the oxygen in building up swells the bag. This can cause bag rupture. Belgian Pat. No. 746,286 provides for an inner compartment wall that is easily rupturable relative to the outer container wall when a slight increase in pressure results due to liberation of oxygen by the hydrogen peroxide, allowing the liberated oxygen to react with one of the color modifiers (e.g. .beta.-naphthol) to prevent rupture of the container wall by explosion. However, this may render the oxidation dye mixture quickly unsuitable for use, as well as accelerate the breakdown of the hydrogen peroxide liberating more gaseous oxygen. The formation of gaseous oxygen leads to the elevated pressures in the container leading to the danger of explosion unless special precautions are taken in the construction of the container.
The present invention provides for the pickup of oxygen from slowly decomposing dilute hydrogen peroxide before it can escape into the portion of the container carrying the oxidation dye solution. Monoterpenoid compounds, and in particular d-limonene, can be used as the oxygen scavenger. As the monoterpenoids are immune to the action of hydrogen peroxide, they can be placed right at the source of the liberated oxygen.
With only minimal amounts of oxygen now able to escape into the oxidation dye solution, greater efficacy for the antioxidants present in the oxidation dye solution can be expected. Stability of the oxidation dye solution is greatly enhanced. In the aluminum-laminated bag, removal of the slowly liberated oxygen can assure negligible bag expansion so preventing finally bag bursting. The separation barrier between oxidation dye solution and hydrogen peroxide is maintained in the package. Rapid hydrogen peroxide decomposition by interaction with the oxidation dye solution resulting in the formation of gaseous oxygen and dangerously elevated pressure is prevented.